Manufacture of sheets, boards, and other materials



May 21, 1929. J. A. STEVENS MANUFACTURE OF SHEETS, BOARDS, AND OTHER MATERIALS Filed May 10, 1928 2 Sheets-Sheet &

INVENTOR i [H h v AHA .1. A. STEVENS 1,714,251

MANUFACTURE OF SHEETS, BOARDS, AND OTHER MATERIALS Filed May 10, 1928 2 Sheets-Sheet 2 INVENTOR (26%.5Sfi52/Q7L5 %Z:5ATTORNEY S 74o the face plate and Patented May 21,"

umrans-srAra-s PATEN Torr e a.

101m A. s'mvans'cr Lowers, MASSACHUSETTS; mam TO rHnuPso comm, i

macros! on SHEETS, nouns, mno'rnnn MATERIALS.

' 6 sheet by a method and witha machine contrived to drawa continuous strip through I a'forming apparatus, and it has or lts ob-;

ject to provide amethod and a machine for this )urpose,"whei'ein the friction inthe 10 forming apparatus with the drawing means located at the fanendof the machine W'lll be greatly reduced Theinvention 1n;gener-, a1 is addressedto the proposition of creating: and maintaining between one or ,both

faces of the continuously form andmov:

v ingstrip,- amd its continuous s aping ortreatiugsurfacesia cush on of gaseous ma-' terialthat greatly facilitates the work of so drawing the strip through the shaping means. w

I'Io these and other ends the HIVQIllZIOD resides incertain improvements and combinations of parts,-all as will be hereinafter a more fuhky'deserib'ed, thenovel features jbe- J ing pointed outin the claims at the end-of the specification. I o

'In thedrlwings: e Fig.- 1 ='s a largely d1agrammat1c V ew partly in section of a -;sheet forming material of a nature to which any; j present mprovements ar'emln v -Fig; 2 is atop up ewthereof';

-Fi 3 is-an end-view (with reference to.

the irection of travel ofzthe, sheet) of a pair of: latens constnucted in. accordance with, an illustratiaigwone embodlment'of, my invention; g V -Fi 4isan end View of onevofthe platens, showing in dottedllinesithe manner in which theyback plate thereof are connected;

Fig. 5 is aiplan viewof an end; fragment of one of the platens 7 I a Fig. 6 is a section-therethrough taken on 4 the .line -66 of Fig; 5,, but. with the "connectionsfor the attachinentliof tlz: soiirce if sn 1 ofigaseousor iqui .ma ria omi tedi 2AM or :all rhollow ,staybolts may be usedxfor this purpose.) I

:Fig.-.-7H-is an enlarged fragmentary detailed section also taken in the-plane of the line 6+6 of *Fig. 5, showing the aforesaid connection, as an example of; one method of connectin the piping ortubing for the admissionoigaseoas or liquidrnaterial. for the out gradesof paint, varnish or any-liquid material Which mightbe Wanted 011 the ma between the liners,"

means, it is hardened. and cut into appropriate lengths.

i928; Serial- No. 276,797."

incidental film lubrication, so to speak, 'and I also' for the admission of; materials -forI.sur-' face finishing ofthe product, such as differterialgas it leaves the platen; system.

Similar reference numerals throughout the several viewsindicate the same parts; Although applicable in other instances,v the present invention has'been designedin the embodiment shown to facilitate the man-- ufacture of a particular type of board sheets or other materialfor building or other con; struction, said board; orother material em:

bodying generally two facings or liners of 'papei'ienclosing an interior bodyof inineral or other material, the latter jaddedffor the purpose of strengthening and stiffening the board and also rendering it water-resist-' ing, fire-resisting, and sound and shock} proofagent. An example of such board is one in which, a mixture containing silicate of soda and dolomitic limestone or other material is introduced between liner sheets and then heat treated at atemperature sufficient tointumesce the said mixture, and cause it, when hardened, to form afirm cellular-mass The heat is'ap plied and the ultimate thickness of-the board o-determined by drawing it through a plurality of steam, or otherwise heatedflp-latens arranged in opposed and'suitably spaced sets. lVhen the board or sheet emerges from these plat -e ens through the functioningofthe drawing before indicated the object of the presentin'vention is'to reducethe" friction incident to drawing the strip through great lengths of such platens, such length being, in the as-im uchxas 160 feet,- u I 4 Referring first to'the showing ofFi s. 1 and 2, 1 indicates a supply :roll furnis ing' contemplated machine,

the upper ,pa'per liner which-passes therefrom [under a guide roll -2,and over a roll 3, 190.7 2

by which. it is reversed in direction and passes to the heatingelement, vhichis also I a ,forming element consisting of "an upper serieso'f steam heated platens 4, and a lower- .Qseries of steam l eated platens 5. A supply i i i roll 6 of paper furnishes the lower liner and the, stripor Web therefrom passes over a roller -7, thence under rollerfi, on bevtween the aforesaid heatingj and forming platens 4'and 5. The rollers .3 and 7 are 10 interior body of the board.

'mouth of a suitable hopper 8, containing the mixture, in a plastic state of themineral substances aforesaid making up the filling or V This material feeds in, under suitable regulations, between the liners and passes with them through the platens 4t and oby which. it is intumesced.

Beyond the platens at the far end of the machine is a hardening oven, indicated generally at 9, through which the composite board indicated generally at in Figs. 1 and 2 is drawn by suit-ably driven and tensioned drawing or feeding rolls 11. The purposeofthe hardening oven 9 in the instance shown is to render the board 'sufli ciently firm to meet the pulling roll Without harm to the interior cellular structure thereof, which has been created by the passage through the heated platens. Nevertheless,

there is a considerable strain upon the board at the pulling. or feedingpoint, dueto the distance between the latter and the front end of the machine from which the materials are initially fed. i 9

In the practice of my present invention, I reduce this resistance, and facilitate the passage of the composite web between the platens, by introducing a volume of air, steam or other heated gaseous material or liquid between one or both surfaces of the liners, and the contiguous faces of the platen, so that a cushion is formed in each instance, over which a product rides in a substantially frictionless and easy manner. To this end I prefer to construct theplatens as shown in detailin Figs. 3 to 7. Each platen unit embodies a baclr plate 12, and a face plate 13 on the inner side, connectedby side walls 1 1, preferably let into grooves or channels in the two plates, and welded thereto at 15. The plates are further intermediately held together by staybolts 16 and 17, the ends of which are riveted into countor-sinks 18 in the plates. A hollow platen is thus produced into which steam or another suitable heating agent may be introduced by supply connections 19, and exhaust connections 20.

The lower platens 5 through extensions 21 at their ends perforated at 22 are carried on vertical guide rods 23 and supported by rigid sleeves 2 1 threaded on the guide rods and resting upon the frame 25 of the machine. Above these extensions further sleeves 26 threaded on the guide rods support helical compression springs 27 encircling the rods, which springs in turn sup,- port similar extensions 28, perforated at 29 on the upper platens 4:, whereby the upper platens are resiliently supported to a predetermined amount. The central .staybolts or connecting elements 17 are preferably tubular as shown in Figs. 6 and 7, so that they are capableof conductinga gaseous or other material from the back plate 12 through to discharge upon the surface of the face plate 13 between the latter and the board material 10. For this purpose a threaded socket fittin 30 is suitably secured to the back plate 12 in'each instance, the passage in said fitting being registered to communicatewith the central passage in the tubular staybolt 17. A nipple 31 provided with a supply pipe 32 coming from a source of steam, air or other suitable gaseous or other material is screwed into the fitting, and thereby a gaseous cushion at a proper temperature not interfering with the heating function and at a suitable pressure is transmitted through each platen, and created upon the face thereof contiguous to the proximate face of the board or other product 10, so that the latter, though controlled as to its thicknessby the degree of separation of the opposing platen, nevertheless floats, as itwere upon the two pads of air or steam or other materlal or liquid, which, though almost imperceptible thickness greatly reduces the friction of the product board in its passage between the platens under the impulse of the drawing rolls 11. The lower platens 5 are preferably relatively thick as shown, and in order to prevent any weaving of the strip during its passage between the two sets of platens, I prefer to provide at each side of the lower set of platens, a side rail or guide rail 33, which may consist of a strip of wood or metal suitably secured to the platen surfaces, as clearly shown in Fig. '3. These strips are of a thickness less than the distance of minimum separation of the two sets of platens, it being necessary, nearly, if they constitute guiding abutments engaging to a greater or less degree the rawedges of the board or strip, which are latertrimmed accurately through the functioning not herein shown, because not necessary to be shown.

I claim as my invention:

1. In the manufacture of boards and sheets, the method of drawing a continuously forming strip between shaping heat transmitting platens which embodies producing a gaseous or liquid cushion between the surfaces of the strip and the contiguous heat transmitting platens.

2. In the manufacture of boards and sheets, the method of drawing a continuously forming strip between heated shaping faces of the platens which embodies introducing under'pressure, a gaseous body between the surfaces of. the strip and the contiguous face plates to produce a frictionless cushion in aid of the drawing means.

3. In the manufacture of boards and sheets, the combination with a pair of platens constituting a shaping means for acontinuously forming strip and means for drawing the strip means or introducing a supply of gaseous material between the strip and the face of a contiguous platen to form a frictionless cushion for the travelof the strip.

" or other material under pressure through one of the platens to the inner face thereof to form a frictionless cushion for the travel of 7 the strip between the latter and the con tiguous platen face.

through such shaping means, of-

5. In the manufacturerof boards and sheets, the combination with a air of platens or hot plates constituting a s aping means for continuously forming strip and means for drawing the strip through such shaping means, oneof said platens comprising a hol low element provided with a tubular connectingmember extending from side toside thereof and having a discharge opening onv the inner contacting face of. the platen, of a supply of gaseous or other material connected to the tubular element to maintain a frictionless cushion of such material between the inner face of the platen and the strip.

JOHN A. STEVENS. 

